domrf_kn_objects is a snapshot dimension (UNIQUE (obj_id, snapshot_date), ~8
snapshots/obj_id). _SUPPLY_BATCH_SQL joined flats to ALL object-snapshot rows
(no o.snapshot_date filter), counting each flat ~8.5x → supply_units_in_radius
inflated ~8.5x, sold_pct_of_supply deflated ~8.5x, is_oversold under-fired
(all user-facing, best_layouts.py:571-611; sold_pct=deals/supply is a raw
ratio so no canceling).
Fix: dedup objects to one row per obj_id (latest-snapshot coords) via
DISTINCT ON in an objects-first MATERIALIZED CTE, then join domrf_kn_flats via
idx_kn_flats_obj. units now = one count per flat (prod cross-check at radius
1.5km: units == count(*) == count(DISTINCT f.id) == 9612 for 65 objects;
correction factor 8.56x at 1.5km, 9.13x at 1.0km). This also aligns the supply
denominator with the deals numerator (_COMPETITORS_IN_RADIUS_SQL already uses
DISTINCT ON latest snapshot).
Perf bonus: objects-first avoids the parallel seq scan of the ~376k-row flats
snapshot. radius 1.5km / snapshot 2026-05-17: 240ms/~28k buffers/6712 disk
reads -> 49ms/1554 buffers/0 disk reads (~5x).
Tests: add SQL-text fan-out guard (DISTINCT ON + MATERIALIZED, no bare
flats->objects join); update stale EXPLAIN mirror in test_phantom_columns.
USER-FACING: best-layouts supply/sold_pct/is_oversold/sell-out-months shift
~8.5x toward correct (frontend BestLayoutsBlock only; ТЗ recommendation + PDF
unchanged — they derive from sum_deals, not supply). Deep-reviewed (APPROVE).
Light1YT
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